This invention relates to a swash-plate compressor provided with novel bearing means for supporting thrust loads caused by the swash plate.
A swash-plate type compressor in general is constructed such that a swash plate is rigidly fitted on the drive shaft of the compressor in a slanted fashion and engages at its fringe portion with pistons received within cylinder bores, whereby rotation of the swash plate causes the pistons to make reciprocating motions within the cylinder bores to compress compression medium and discharge same.
Conventional swash-plate type compressors of this kind include a type that the drive shaft is inserted in axial through bores formed in two cylinder blocks combined together in axial alignment, a swash plate chamber being defined between the combined cylinder blocks, within which a swash plate is arranged, while the swash plate is fitted aslant on the drive shaft. According to this type, the drive shaft is supported by radial bearings in the radial directions at radial bearing portions provided within the axial through bores, while supported in the axial or thrust-applying directions by thrust bearings at opposite sides of the swash palte.
The above thrust bearings are usually formed of needle bearings which are interposed between the end faces of the central seating portions of the combined cylinder blocks and the end faces of the boss of the swash plate for supporting thrust loads caused by rotation of the swash plate. These needle bearings, however, have a structural drawback that they produce large noise during rotation of the swash plate. Moreover, the needle bearings are expensive, like needle bearings in general.
To avoid the above drawbacks in the needle bearings, it has been proposed to interpose thrust plane bearings each formed of an annular plate member having substantially the same diameter as those of the central seating portions of the cylinder blocks, which are interposed between the end faces of the central seating portions of the cylinder blocks and the end faces of the boss of the swash plate. However, the load distribution can be uneven over the bearing surface when the swash plate is axially angularly displaced from its usual or proper position during its rotation, resulting in a large amount of abrasion of the bearing surface. This shortens the effective life of the bearing. Therefore, thrust plane bearings are not suitable for use in the above-mentioned type compressor, either. Such being the circumferences, thrust needle bearings are still used in the above-mentioned type compressor.